CVE-2019-20373

Local root escalation via empty username parsing

Published Jan 9, 2020 · Updated Aug 5, 2024

Privilege escalation in LTSP LDM 2.18.06 and earlier allows local users to obtain root access on fat clients through an incompatible login shell. The run-x-session hook parses SSH server responses with Bourne-shell syntax and accepts an empty LDM_USERNAME when the login shell does not support that syntax. Exploitation requires a local LDM account configured with an incompatible shell, and successful exploitation grants full control of the affected fat client.

CVSS severity7.8
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in LTSP LDM 2.18.06 and earlier allows local users to obtain root access on fat clients through an incompatible login shell. The run-x-session hook parses SSH server responses with Bourne-shell syntax and accepts an empty LDM_USERNAME when the login shell does not support that syntax. Exploitation requires a local LDM account configured with an incompatible shell, and successful exploitation grants full control of the affected fat client.

The record

CVE
CVE-2019-20373
Published
Jan 9, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 9, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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